How Vulnerable is Your House to Termites?

The termites we have in Nebraska live in the soil in a colony with hundreds or thousands of individuals. Termites are important decomposers—they recycle dead plant materials and return nutrients to the soil. Termites are rarely seen and are a problem only when they feed on our structures.

In Nebraska, termites are not very active during the winter when the soil is cold or frozen. But, when temperatures warm in the springtime, hungry termites aggressively begin searching for food: wood, cardboard, paper or other types of cellulose. Termites have microbes in their gut which helps them turn cellulose into simple sugars, which they can digest.

Termite researchers used to think termites wandered randomly through the soil. We know now this isn't really true. Instead, termites move in predictable ways to methodically divide and subdivide the soil to make sure they search every square inch of soil. If there's a colony in your yard, termites eventually will bump into your house.

To keep from becoming dehydrated, termite workers travel through the soil in mud tubes which they make with mud, saliva and feces. They keep the humidity in these mud tubes moist.

In a perfect termite world, these soft-bodied workers would always stay in the soil, feeding on dead trees that have fallen to the ground. But, in urban areas, we clean up our landscapes so there are no dead trees lying around for them to eat. So, being the survivors they are, they search above the ground for wood. Any untreated wood that touches the soil is a potential termite conduit into the house.

To get into a structure, termites must build a mud tube over the foundation or they must have a crack in the foundation or floor. Termites can squeeze through a 1/32-inch crack.

Some foundations are better at resisting termites than others:

- Poured concrete foundations are best, as long as there aren't cracks in the concrete. Rebar reinforced concrete will help prevent cracks.

- Hollow block foundations are more risky, because the mortar that holds the blocks together may become weakened over time. The other problem with hollow block foundations is if the termites get inside of the hollow block, they can travel vertically into the house with no apparent signs of mud tubes.

- Slab foundations are often close to the soil, which means termites can tube fairly easily into the structure. Slabs may have holes and cracks which provide a way into the structure. The basement floor almost always has a crack where it meets the side of the foundation. A susceptible location is often where the garage slab and house are attached.

- Crawlspaces are problem areas because they are often humid and cannot be inspected very well. They are also difficult to treat.

Another problem area is called a "dirt-filled" porch. Many newer homes have this type of porch. During its construction, workers filled in the porch with soil and then poured a concrete "cap" on top. The dirt-filled porch is a problem because the soil (in the porch) is often higher than the structural wood of the house and is next to the house.

Some people believe brick houses are resistant to termites, but this isn't true. Because the structure of a brick house is made of wood, termites will feed on it just as easily as other houses. In fact, a brick house is at risk because termites can travel behind the brick veneer to get into the house without being seen.

How vulnerable is your house?

- What type of foundation do you have?

- Do you have an inaccessible crawlspace?

- Do you have wood touching the soil near the house? Researchers say 90% of termite infestations can be traced back to wood in the soil.

- Do you have moisture problems near the house that may draw termites?

- How old is your house? The older the house, the more likely it is to have foundation problems. However, we also see termites in newer homes.

If your house is vulnerable to termites, you may be able to prevent termites yourself by eliminating wood-soil contact or moisture problems. But, it is important to be vigilant and watch for signs of termites during the warmer months.

This resource was updated September 2009 and originally appeared in the April 2008 Lincoln Journal Star Newspaper Sunday edition. For information on reproducing this article or using any photographs or graphics, read the Terms of Use statement

The information on this Web site is valid for residents of southeastern Nebraska. It may or may not apply in your area. If you live outside southeastern Nebraska, visit your local Extension office